英语为什么不用when

英语为什么不用when 英语填空,while和when的用法,为什么2只能用when不用while when time is gone,为什么不用spent 英语,When and where to go for the holiday has not been decided为什么用has 不用have 英语中when的用法Please tell him when the train will arrive.I want him to come to the station meet me.句中用when ,when作为从属连词,作为宾语补足语吗,为什么不用time 为什么不用does?when __the Quiz show on?要用is 为什么第7题用when而不用if? when is his birthday? 句子开头为什么不用what? while your parents are away 为什么不用when When i am middle aged.为什么不用middle age呢? Please watch my clothes when i swim.为什么不用swimming? since when do you guys know each other为什么不用过去式这什么这个地方不用过去式, 英语时态：I wanted to know when they would go to see the great wall为什么这句话的从句用一般现在时,不用过去时? 英语句子Do you know when and where he was born?哪个主句?为什么用he was born,不用he has borned 救人如救火初三英语father doesn't tell me when he _____from here为什么写comes 而不用will come could you tell me when would you be visiting XXXX为什么不用when will it was yesterday when he play这句话为什么不用when?要改成that? she will get nervous when speaking in public为什么用speaking而不用when she spoke